This invention relates to a lifting apparatus. More particularly this invention relates to a portable, combination lifting apparatus and material handling cart.
Portable lifting devices are known, for example, such as those disclosed in U.S. Pat. Nos. 4,375,248, 4,427,093, 4,458,786 and 4,619,346 all of which are relatively large, heavy structured devices mounted on wheels and having different extending and retracting lifting mechanisms for positioning a platform. As is well known, these types of devices are rather top heavy and can become substantially unstable especially when fully extended and heavily loaded. Most such devices have only one support or stabilizing means usually in the form of vertical legs mounted to the base which are extended to contact the ground. Typical stabilizers or levelers are shown in U.S. Pat. Nos. 4,427,093 and 4,375,248. These legs, because they are vertically orientated, do not always provide sufficient vertical stabilization to such devices. The device is still able to tip about the legs when subjected to horizontal loads with the lift fully extended. Further, in a pantograph-type device such as in U.S. Pat. No. 4,375,248, the linkage is supported solely at its attachment to the base and is subject to pendulum-type swaying and possible tipping.